Electric piano.



H. K. SK NDE-EL, ELECTRIC PIANO. APPL'IOATION FILED JULY 5, 1910.

6 SHEETSSHBET 1.

Minesses lnvenior;

Patented NOV. 26, 1912.

H. K. SANDBLL.

ELECTRIC PIANO.

APPLICATION FILED JULY 5, 1910.

1,045,444. Patented Nov. 1912-.

M'Zrzesses flwenl or:

i QTLTH L $5211 a. 14% 1 4 $172 w,

H. K.-SANDELL.

ELECTRIC PIANO. APPLICATION FILED JULY 5, 1910.

6 SHEETS-SHEET 3.

Henry K.Sandeu,

Patented N0v.26, 1912.

H. K. SANDELL.

ELECTRIC PIANO.

APPLICATION 211.111) ULY 5, 1910.

Patented Nov. 26, 1912.

6 SH BETS-SHEET 4.

M'Znesses H. K, SANDBLL.

ELECTRIC PIANO.

APPLICATION num- JULY 5, 1910. 1,045,444. Patented Nov. 26, 1912.

6 SHEETB-SHBET 6.

H. K. SANDELL.

ELECTRIC PIANO.

APPLICATION 211.29 JULY 5, 1910.

1,045,444. Patented Nov. 26, 1912.

6 SHEETSSHIIET 6.

UNITED STATES PATENT UFFICE.

HENRY SANDELL, or CHICAGO, ILLINOISLASSIGNOR ro MILLS NOVELTY. ooMPAuY,

or'crncao rrmnors, a CGBPDEATIQIQ' ore ILLINOIS.

iiroicraic static,

To all whom it may concern:

Be it known that I. HENRY K. Simmer! a citizen of the United States, residing at Chicago, 111 the county of Cook and State of Illinois, have inventeda new ano useful more particularly, in the class ot-pianos which are played by a traveling music-sheet,

through the medium-of Which the hammers I areactuated electrically or otherwise.

While the application of the more ion portant features of improvement is not necessarily limited to electrical means for playing the instrument thrbugh the medium of the perforated variety of music-sheet, the

invention was especially devised for that ap plication, it being practically embodied in a piano the hammers of which are actuated by electromagnets included in parallel circuits, or each in a branch-circuit of a gen orator contained in the common or vmain part of the circuit, adapted to he closed through the perforations in a traveling music-sheet as they register, in the travel of the sheet, with circuit-closing contact mechanism between which the sheet passes.

The present" invention relates primarily to mproved means, controlled by the traveling music-sheet, for modifying the tone of theinst-rumentin accordance with the re-' quirements of the musimbeing performed by regulating the force of stroke of the hammers; and other features of improvement Will be hereinafterpointed out.

In the accompanying drawings, F igure, 1

is a view in front elevation of a piano of the upright variety embodying my invention; Fig. 2,.a view of the same in side elevation With a side of the casing broken away; Figs. '3 and 3 present, respectively, in vertical sectional elevation, the improved means for regulating the force of stroke of the hammers of the piano-action and, in front elevation, an electromagnet device for operating said regulating means; Fig. 3 is anenlarged section on line 3*, Fig. 3:, Fig. 4: shows, by an enlarged broken, sectional view in side elevation, one of the electromagnet-devices illustrated in Fig. 3, With the pivotal armature and partscotiperating therewith in normal position; and Fig. 5, isa plan View of the same; Figs. 6 and 7 are, respectively, views in side and frontele- Specificatio i of Letters latent.

wound with light 1 multiple.

Patented Nov. 26, 1912.

Application filed July 5, 1910. Serial 570,432. i

ration of thee electromagnet-device forcontrolling the string-dampers of the instrument, and Fig. 8' presents-a diagram of the electric circuits for controlling the electromagnet-devices .WlliC-ll operate the piano.-

..action and the string-dampers and control the striking force of the hammers.

The action" shown; and Whichis denoted A, as a Whole, in Figs. 1 and 2, is one in common use in upright pianos, except that for the sake of compactness, more particularly to adapt the instrument to be cooperatively combined, for duo or accompanlment play ng, with an electric selfplaying violin, it divided into an upper section A? and alowersection A so arranged. relatively, as to cause alternate hammers of the two sections to register with successive same pitch, of the'ii' strument. Adjacent to each hammer ofthe action are supported two electroinagnet-coil.s 9 and 10, these coils forming, respectively, an outer row and an inner row for the hammers of each section of the action, the coils 9 being rendered of relatively low resistance by Winding their cores w th heavy ire and the code 10 being Wlrft0 increase their resistance, all for p: plained; andthe two i ils of difierent resistance for each hammer are connected in The insulated Wires for all of the hammer-actuating electromagnets are housed in metal boxes 11 and 12, of rectangular cross-section, supported above the respective rows of magnets, and provlded with fronts-ails 13 of insulating material carrying on their 'frontfaces rows of inclined n'ietal strips 14: having bindingposts,

on their lower ends for connecting the Wires of the.electromagnets to-the strips: to the opposite ends of the inclined strips the ivires in the boxes are connected through thereof are connected to a ditlere'nt strip 14. A bar 15, for performing the stop-function hereinafter described, and which is pro- :rings, or sets of strings-ofthe s hereinafter exi iont- Walls of the boxes as indicated Fig; The coils 9 and. 10 of each pa r vided with a sot'tmuhher sheath 16 to elecv- ,trically insulate. and cushion itnextends iei'igthiyise alongeacl" row of the electromagnets 9.. 1G, in, ad"; m etand above the 15,, et ding hacltwardly s n .i on is,

whic ions the bar is pivotally supported on standards pivotal points two corresponding arms of- 17, to adapt it to be rocked. Behind their I coil 9 forms with the companion-coil immediately behind it a pair having a common armature 21, depressed between its ends, as shown at 22, to bring it closer to the magnet-poles and increase its attractiveness. The armature 21 is fulcrumed at 23 on the upright arm of an iron bracket 24 carrying the pair of magnet coils on an angle iron support 25, one of which supports is provided for each row of the pairs of coils. In the upper face of each armature 21 is inserted, near its free end, a platinum contact-plate 26. Each armature 21 is embraced between the arms of a rectangular iron yoke 27, pivotally and insulatingly supported at the bent rear ends of its arms,

as represented at 28 (Fig. 4), on the upright arm of the bracket 24, which is embraced between the yoke-arms; and the forward, closed end of the yoke has attached to'it, as by a pin 29, a rectangular metallic finger 30 extending backwardly over the top of the free-end portion of the armature and carrying a platinum contact-point 31 to engage the insert 26, and a similar finger 32 extended across the plane of a stop-rod 15. As will be observed, thearmature and its yoke turn on different centers, at 23 and ,28, respectively, to cause, when they are moved, the point 31 to rub against the surface of the plate 26 and insure good contact.

One terminal of the winding of each coil 9 is connected with the respective yoke at 33, its opposite terminal, as also a terminal of the winding of the coil 10, being connected with a strip 14, while the opposite .terminal of the coil 10 is connected to the iron framework.

A stem 34 extends backwardly from the rear end of each armature 21, to which it is rigidly united to move therewith, the stem carrying on its rear threaded end an adjustable weight 35 to overbalance the armature and cause it to normally incline upwardly relative to the plane of the upper surface of the poles of the two magnet coils to which it belongs These stems of the upper row of armatures carry buttons, 36 (see, particularly, Fig. 3,) extending upwardly from them to engage, from underneath, by movement of the armatures under attraction, the usual wippens of the pianoaction, thus, by such attraction of the armatures in the upper row thereof, to cause the hammers to strike the alternate strings of the instrument. From the lower armaturestems 34 extend upwardly rods 37, passing loosely through an interposed perforated guide-board 38 and carrying on their upper ends buttons 36 to engage hammer-actuating levers of the piano-action for working the hammers which alternate with those moved by the upper row of armatures.

As will be understood from the foregoing description. each time a pair oft'hecoils 9, 10, is energized, their armature is attracted and with it the respective yoke 27. In fact, the armature and yoke together compose an armature formed of two separable movable parts or sections. By the resultant movement of the section 21, its stem actuates the hammer controlled by it to strike a string. The force of the hammer-stroke is greatest when the respective stop-rod 15 is in its lowermost position and is slightest when the rod is in its highest position, both of these positions being indicated by the dotted representations of the rod in Fig. 4f, the full-line representation thereof being its intermediate normal position. The reason for this difference in the hammer-stroke is that when the stop-rod is in the lowest position it is not encountered by the finger 30 of the respective armature-yoke 27, until just before the complete downward movement of the armature, so that the greater force of the coil 9 continues to advance the armature-section 21 throughout its movement and causes it to actuate the respective hammer forcibly to produce a loud tone by the hammer-stroke. Vith the stop-rod raised above its lowermost position, however, the encounter therewith, in the downward movement-of the yoke, of the finger 32 will arrest the yoke and cause the continued movement of the armature 21 to separate the plate 26 from the contact-point 31, tliereby cutting out the coil 9 and leaving the coil 10 in circuit to complete the attraction of the armature with weaker power and therefore causing it to actuate the hammer with weaker force, producing a softer tone, though without shortening the regular full stroke of the hammer. Obviously, the higher the position of the rodl5 the sooner will it effect cutting out of the coil 9 and leave the highresistancc coil 10 to operate the hammer, and the softer, therefore, will be the tone produced by the hammer-stroke.

The advantage of the described arrange-- with the coils 9, 10, as hereinafter described. with particular reference to the diagrai'n in Fig. 8. The threefold advantage referred to consists, first. in enabling control to be had of expression in playing the instrument;

second, in economizing in current. since the high-resistance coils, which are 1 used the most, use less current than'the low-resistance I ones; and, third, in preventing harmful sparking at the brushes 4.1 in the frequent "breaking of the circuit there which would be sufiiciently' violent, it the high-resistance coils were out out at that music-sheet. v v v The matter of setting the stop-rods -to difierent positions in playing the instrument is automatically efl'ected by the perforated point,t0 burn the traveling music-sheet through the medium of the mechanism shown in Fig; 3 which is supported in p the bott'ornj portion of the piano-case.

' the strings with -On an iron bed 4-2, rigidly sirpported in the piano-case and having a standard 43 rlsing from 1t, 18 fulcrum ed midway between its ends on. the standard an armature-lever 44- normally heldresiliently in horizontal position by an expans1o1i-spr1ng 4E5 connecting one end of the lever with the bed. With this same end of the lever ld the rod 20 has an adjustable and flexible connection, as shown at 46 in Fig. 3?; and the opposite end of the lever carries'averti cal rackel' meshmg with a pinion, indicated at 4;S, on a ro-.

side of the s andard. The two electromagnet-spo'ols 53 are connected in series, as are also the two spools 54.

'With the 16; r 44, in itsnormalhorizontal} position, the rod 20 holds the stop-rods 15. in their intermediate position, wherein they permit moderately loud playing of the instrument by caus ngthe hammers to strike brute force. l Vhen the traveling music-sheet closes the circuit to energize the electromag'net 53, they attract the adjacent arin of the armature-lever 44, thereby raising itsopposite arm and with it the rod 20 to depress the stop-rods 15, with the result of augmenting the force of stroke oftlie hammers in action and thus increasing the loudness of playing; and when the.

traveling sheetcauses the coils 54 to be energized, they attract the arm of the lever eta ad acent; to, them; thereby causing the v rod 20 to raise the stop-rods 15 and moderate accordingly the striking-force of the hammers in action. The rack and pinion inecha nisn'i at one end of the armature-lever acts as a brake to'prevent objectionable sudden force of the electroinagnets;

A substitute for the loud. pedal of the ordinary piano is provided for automatic operation in the form most clearly illustrated in Figs. 6 and 7, and also shown in Figs. 1 and 2: On a support 55,'which maybe a continuation of the bed 42, in the bottom part of the piano-case toward one side there of, rise a pair of similar electromagnetspools 56, wound as described of the spools anda single electromagnet-spool 57, wound like the spools 10 to render it relatively connected in multiple. Extending from the support- 55 at right-angles to and, below; the

net-spools 58, 58, connected in series and presenting their poles to a vertical armature59 pivoted between its ends at GOand held normally away from the poles *bya' spring interposed at61, the upper endf-of ably engage the free end of an armature 63 pivoted at its opposite end, as shown at 6- to extend over and be common to the poles'of the spools 56,57. A stoparm 65 cooperates with acontact-finger 66 at its free end to cut out the spools 56, as hereinafter described. A rod 67 extends upwardly from the armature 63'near itsfree end and connects it at 68 with the rocking usual in anuprightpiano.

By the constructlon gust described it will with. he magnet 57, will start themove: ment of the armature 63, and as soon as it has been started the circuit through the magnets is broken and consequently the armature moves the-remainder of the distance only under the pull ofthe magnet 57. By using only the magnet 5' to continue the movement the pounding of the parts is tained through the magnet 57- for a suflicient length of time to complete the movement oft-he armature 63, it isnecessarythat the catch 62 operate t retain the ari'nature in its position against the magnets until it is desired to release the same. e

The operation of this device is substantially the same as that of the-expressiondevice hereinbefore described, for varying the force of the hammer-strokes; that is to traveling music-sheet by engagement with the roller d0 of a contact-brush41 connected .vwith'the coils 5G,.-57,. theyattract the armamovements thereof under the attractive" 9 to render them relatively low-resistant,-

high-resistant, these spools 56 and 57' beingv spools and 57 are two similar electromag-- the armature forming a catch 62toreleasbar carrying the series of stringdampersas,

be se n that the two magnets 56, together prevented. Since the circuit is only niainsay, when the circuit is closed through the ,the dampers from the strings.

under the attraction of its magnet by theinterposed stop 65, whereby these coils are cut out, leaving onlythe coils 57 of greater resistance in circuit, and the catch 62 is caused by its spring 61 to engage the armature 63 and hold it down until the catch is released. This release is effected at the proper time by closing the circuit through the music-sheet to energize the coils 58, 58 to attract the catch-armature 59 and withdraw the catch from the armature 63, which then rises to its normal position under the usual spring-tension of the dampers and restores the damper-bar to its normal position.

The further description of this invention is with particular reference to the circuitdiagram of Fig. 8. The electric motor D is suitably geared to the music-sheet feed-device C, to drive the latter for effecting the travel of the sheet between the roller 4:0 and contact-brushes 41 and 41. For starting and cutting out or stopping the motor by hand, a push-button 68 is manipulated to make contact at the points 69 and 70, thereby closing the motor-circuit which may be traced as follows: From one side of a generator, indicated at E, over a wire 10 and branch w through an electromagnet 74 provided with a pivotal armature 75; from the electrom'agnet 74 over wire w through the pushbutton 68 and thence over wire tu to the opposite side of the generator. By thus energizing the electromagnet 7st to attract the armature 75, the latter releases the pivotal spring-pressed armature 76 of an electromagnet 77, causing the last-named armature to contact at 78 with the wire 10. Upon release of the button 68, when it separates from the contact-points 69, 70 and cuts out the electromagnet 74, the motor-circuit is thus closed over the wire 'w and armature 76,

, thence over wire 20 connecting that armature with one side of the motor, to the opposite side of which the wire w is connected.

To cut out the motor and stop the operation of the machine, a push-button 71 is manipulated to make contact at the points 7 2 and '73, thus connecting wire 10 with a wire wileading to a contact-brush 41 in line with the series of contact-brushes 4:1. The wire 20' has a branch-connection w with the electromagnet 77, from which a wire to connects with Wire 11) at the armature 76. Thus, by pushing the button 71, the electromagnet 77 is energized to attract the armature 7 6 and break the contact at 78, whereupon the armature 75 engages and locks the armature 76 in its attractedposition.

Each of the hammer-actuating electromagnet-devices, as also the expression-controlling device and the damper-controlling device, is connected by a separate wire with a diflerent contact-brush 41, as will appear on inspection of the circuit-diagram, so that the music-sheet, in traveling between the the motor is automatically cut out, since thereby the electromagnet77 is energized to attract the armature 76 and break the contact at 78.

The device indicated at F in Fig. l-is a mere switch .for turning, stopping and reversing the actioirof the music-sheet feed by which the sheet is wound from one roller upon another, but neither it nor the feed form any part of the" present invention, and need not, therefore, be h :ein described.

What I claim as new and desire to secure by Letters Patent is: v

1. In combination with a piano-action,electrical hammer-actuating mechanism therefor comprising an electric circuit, an electromagnet therein having coils of difi'erent resistance, said coils being connected in parallel, an armature comprising sections movable relatively to one another, said sections jointly controlling the current through one of the coils, both sections being simultaneously movable when the magnet is energized, and a stop in the path of one of said sections to stop said section without stopping the other section, thereby interrupting the current through one of the coils.

25111 combination with a piano-action, electrical hammeractuating mechanism therefor comprising an electric circuit, an electromagnet therein having coils of dift'erent resistance, said coils being in parallel branches, an armature comprising sections movable relative to one another, said sections being electrically connected in said circuit in series with the coil in one branch, both sections being simultaneously movable when the magnet is energized, and a stop in the path of one of said sections to stop said section without stopping the other section and open the circuit of the coil in said branch.

3. In combination with a piano-action, electrical hammer-actuating mechanism therefor comprising an electric circuit, an

electromagnet therein having coils of different resistance, said coils being 1n parallel branches, an armature for said magnet incense through said coil, the armature and yoke being sim'ulta'neous-ly movable when the magnet is energized,-and"a stop in the pathof the yoke to stop the yoke without stop ping the armature.

'4'." In combination with a"piano-action', electrical hammer-actuating mechanism therefor comprising anelectric circuit, an

" electromagnet therein having coils ot'different"-resistance, said coils being'in parallel branches,an armature having a hamf mer-actuating stem, av yoke embracing the armature, said armature, and yoke being independently tm'ovable on different centers, said armature and yoke being'electrically in series with each other and with the coil in one branch, a separable contact between the free ends of the yoke and armature, both said armature and yoke being simultaneously movablewhen the magnet is energized, and a stop in the path of said yoke to stop said yoke without stopping the armature and thereby separatethe contacts and deenergize the coil in series with the armature and yoke.

5. In combination with a piano-action,

electrical hammer actuating mechanism therefor comprising an electric circuit, an electromagnet therein having coils of different resistance, said coils being in parallel branches, a pivoted armature, a pivoted yoke embracing the armature, a hammer-actuating stem provided with an adjustable weight upon it carried by the armature, said armature and yoke being in said branch and connected in series with one another and the coil in said branch, both the armature and yoke being simultaneously movable when the magnet is energized, and a stop movable to different positions in the path of the yoke; to stop the same without stopping the armature and thereby deenergize the coil in series with the armature and yoke, and electrically operated means for moving said stop.

6. In combination with a piano-action, electric l hammer-actuating mechanism having a moving part, a rocking stop-bar nzovable to difierent positions in the path of said moving part to vary the force of the hammer-stroke, an electrical device for mov ing the stop-bar, comprising an armature fulcrumed between its ends, a connection therefrom to the stop-bar, electromagnet coils on'opposite sides of the fulcrum and having the armature in common, and means for energizing said coils for the purpose set forth.

7. In combination with a piano-action, electrical hammer-actuating mechanism hav- .ing "the stopbar, comprising a spring ba' nets on-opposite [sides of the fulcrum having the armature in' cornmomfan'd means 5: for energizing said m'agnets'for the purpose" set'forth. '7

ture fulcrumedbetwe'en its-ends andpr vided on one end with a," rack-and-piniona ing a moving part, a rocking stop-bar mov able to different positions in the pathbfsaic mer-stroke, and an' electrical device f "n v anced' armature hemmed bet-ween'fiits end,

a connection therefrom to the stop-bane brake; device on the "armature, electnom 8'. In combination I I v; electrical "hammer 7 actuating? fmech'ani having a moving part, a rocking stopliar movabletodiflerent positions in the path f said moving part to vary the force ot 't hammer-stroke,a1id an" electrical device or moving the stopbar, comprising an brakedevice, and electromagnets on oppo' site sides of the fulcrum, having the armature in common, a rod connecting the armature with the stop-bar, and means for energizing said magnets for the purpose set forth,

9. In combination with a piano-action, electrical hammer actuating mechanism therefor, an electric circuit containing said mechanism, and an electric damper-operating device comprising an electric circuit, an electromagnet therein, having coils-of different resistance connected in parallel, an armature common to said coils, a contact normally engaging said armature and mounted so that the engagement will be broken when the armature is attracted toward its magnet, said armature-and contact being in circuit with one of the coils, and means connecting the armature with the damper.

10. In combination with a piano-action, electrical hammeractuating mechanism therefor, an electric circuit containing said mechanism, and an electric damper-operating device comprising an electric circuit, an electromagnet therein having coils of different resistance, said coils being connected in parallel, a pivotal armature for said coils, a contact normally engaging the armature, said armature and contact being in the circuit of the coils and connected in series with one coil, a rod connecting the armature and the damper-bar, an electromagnet extending crosswise or" said first-mentioned electromagnet, a pivoted armature for saidlast- ,i'nentioned electromagnet, a catch on said armature adapted to engage with the first mentioned armature, and a circuit for energizing said last mentioned electromagnet.

11,. In combination with a piano action, electrical hammeractuating mechanism therefor adapted to be actuated by a traveling musicsheet, comprising an electric circuit, contact members in said circuit between which with a" pianmacti n,

the music sheet travels, rows of pairs of elec tromagnet coils, the members of each pair being of relatively high and low resistance, one

ture for each' pair of said coils, a contact normally engaging each armature, each armature and contact being in circuit with one of the coils of its pair a stop bar extending lengthwise of said rows and means for moving the stop bar to difi'erent positions in the paths of the armatures to separate the armature and its contact.

12. In a piano, the combination of a piano-action divided into a plurality of sections one above the other, electrical hammeractuating mechanism therefor adapted to be actuated by a traveling music-sheet, comprising an electric circuit, contact-members 1n said circuit between which the musicsheet travels, a row for each section of pairs of electromagnet coils, the members of each pair being of relatively high and low resistance, one pair for each hammer of the action and each pair being connected With a different contact-member, a hammer-actuating armature for each of said pairs, a contact normally engaging each armature, each armature and contact being in circuit with 7 one ofthe coils of its pair, connected stopbars extending lengthwise of said rows and movable to diiferent positions in the paths of the armatures, and electric means operatively connected with said bars for moving them to'difl'erent positions in the paths of the armatures to separate the armatures and contacts, for the purpose set forth.

HENRY K. SANDELL. In presence of J. G. ANDERSON, R. A. SOHAEFER. 

